JPH1123606A - Yaw rate operating unit for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate the yaw rate of a vehicle through a simple arrangement. SOLUTION: A yaw rate γa detected by a yaw rate sensor 11 is detected during stoppage where the net yaw rate is zero in order to correct a detection reference point through learning thus determining an initial corrected detection yaw rate γa1 . The initial corrected detection yaw rate γa1 is subtracted from a yaw rate γb calculated based on the difference between the left and right wheel speeds Va, Vb within a specified time after starting a vehicle. Subsequently, a corrected calculation yaw rate γb1 is determined by removing the error due to abrasion of the wheel through learning correction. Finally, a yaw rate γa2 is determined when the vehicle is traveling through learning correction with reference to the initial corrected detection yaw rate γa1 and the corrected calculation yaw rate γb1 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for calculating a yaw rate acting on a vehicle during traveling.

[0002]

2. Description of the Related Art Even if a road on which a vehicle travels is a curved road, or a straight road, the vehicle runs in the lateral direction (width direction).
, A yaw rate is generated for this vehicle. Conventionally, this yaw rate has been detected by a yaw rate sensor. That is, the yaw rate sensor detects the rotational speed of the vehicle around the vertical axis, and outputs the detected value to the control unit to be used for braking force control, steering force control, and the like.

[0003]

However, in this yaw rate sensor, generally, a piezoelectric element for both vibration and detection is attached to two adjacent surfaces of a quadrangular prism as a vibrator, and a voltage is applied to the piezoelectric element. When applied and vibrated, a rotational force is applied to the metal column, and a Coriolis force is generated according to the rotational speed. At this time, each current flowing through the two piezoelectric elements is detected, and the difference between the currents is determined to obtain the Coriolis force. The force is detected, and this signal is converted into a voltage signal and output. However,
Since the yaw rate sensor has the above-described configuration, it is sensitive to a change in ambient temperature, and an error occurs in the detection value due to a shift of the detection reference point. Therefore, it is necessary to correct the detection value of the yaw rate sensor according to a change in ambient temperature.

In order to correct the zero point of the yaw rate sensor, for example, Japanese Patent Laid-Open Publication No.
No. 73 is disclosed. The "Yaw rate sensor zero-point drift correction device" described in this publication
A part of the detection signal of the yaw rate sensor is input as an operation signal to an arithmetic unit through a filter circuit configured by connecting a plurality of filters in three stages in series, and the offset of the detection signal is corrected, and the zero point drift of the yaw rate sensor is reliably corrected. To do it. However, the "zero-point drift correction device for the yaw rate sensor" corrects the zero-point drift only with the frequency component by the low-pass filter, and the zero-point drift may not be corrected accurately.

Further, the yaw rate of the vehicle can be obtained in a linear form derived from the geometrical relationship at the time of turning of the vehicle based on the rotation difference between the left and right wheels without using the yaw rate sensor. However, since the tires of a vehicle are worn over a long period of use and the amount of wear is not constant between the left and right wheels, the yaw rate obtained by this method includes the effect of the amount of tire wear. Increases in proportion to the vehicle speed, and the detection accuracy of the yaw rate decreases.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a vehicle yaw rate calculation device capable of calculating a vehicle yaw rate with high accuracy with a simple configuration.

[0007]

According to a first aspect of the present invention, there is provided a vehicle yaw rate calculating apparatus for achieving the above object.
A yaw rate sensor and a wheel speed sensor are provided, and a yaw rate calculating means for calculating a yaw rate of the vehicle from a difference between left and right wheel speeds detected by the wheel speed sensor is provided. When the vehicle stops, an initial detection yaw rate error learning means learns an error of the detected yaw rate. The detected yaw rate initial correction means corrects the detected yaw rate based on the learning value, while the calculated yaw rate error learning means calculates the yaw rate error based on the detected yaw rate corrected by the detected yaw rate initial correction means within a predetermined time after the vehicle starts running. The calculated yaw rate correction means corrects the calculated yaw rate based on the learned value after a predetermined time has elapsed since the start of traveling of the vehicle. The yaw rate learning means is based on the calculated yaw rate corrected by the calculated yaw rate correction means. Learns detection yaw is detected yaw rate initial correction means is corrected, detecting yaw rate correcting means are so as to correct the detected yaw rate is detected yaw rate initial correction means is corrected based on the learned value.

Accordingly, the error of the detected yaw rate is corrected when the vehicle stops, and the calculated yaw rate is corrected based on the corrected detected yaw rate within a predetermined time after the vehicle starts running. Corrects the detected yaw rate based on the corrected calculated yaw rate, corrects the error due to the temperature change to the yaw rate detected by the yaw rate sensor, and calculates the wheel wear amount to the yaw rate calculated from the difference between the left and right wheel speeds. By correcting an error proportional to the speed, a highly accurate yaw rate can be always obtained.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a control block diagram showing a vehicle yaw rate calculating device according to an embodiment of the present invention, and FIG. 2 is a flowchart showing a control method by the vehicle yaw rate calculating device of this embodiment.

[0011] yaw rate calculation device for a vehicle of this embodiment, as shown in FIG. 1, a yaw rate sensor 11 for detecting the yaw rate gamma _a vehicle, the wheel speed V _a of the left and right of the vehicle, wheels for detecting the V _b has a fast sensor 12, the yaw rate calculation section 14 calculates the yaw rate gamma _b of the vehicle from the wheel speed difference between the left and right of the respective wheel speed sensors 12, 13 has detected. In general, the detection reference point of the yaw rate sensor 11 is shifted due to a temperature change depending on a mounting position on the vehicle.
The detected yaw rate gamma _a is thus error occurs when the ambient temperature is increased by. On the other hand, since the left and right wheels are not constant in the amount of wear due to long-term use, the left and right wheel speeds V _a ,
The V _b will include the impact of the wear amount of the tire, the right and left wheel speeds V _a, yaw rate determined from the difference between V _b gamma
_{In b} , an error proportional to the speed due to the amount of wheel wear occurs.

Therefore, in the present embodiment, the detected yaw rate γ _a of the yaw rate sensor 11 which is susceptible to a change in ambient temperature is learned and corrected based on the detected yaw rate at the stop when the true value of the yaw rate is zero. The yaw rate γ _b calculated from the difference between the left and right wheel speeds V _a and V _b , which is susceptible to the amount of tire wear, is determined based on the detected and corrected yaw rate γ _a within a predetermined time after the vehicle starts moving. Learning correction. During the running of the vehicle, the initially corrected detected yaw rate γ _{a1 is} subjected to learning correction based on the learning corrected calculated yaw rate γ _b1 to remove the influence of ambient temperature change, thereby achieving a highly accurate yaw rate γ _a1 . γ _a2 is determined.

[0013] That is, during the pre-stop vehicle start, since the true value of the yaw rate is always zero, if the yaw rate gamma _a yaw rate sensor 11 detects at this time is not zero, the value is the error value C _a . The detection yaw rate initial correction means 16 corrects the yaw rate gamma _a yaw rate sensor 11 detects based on the initial detection yaw rate error learning section 15 is obtained by learning error value C _a, the initial correction detection yaw rate gamma _a1 Ask.

On the other hand, within a predetermined time (for example, 100 seconds) after the vehicle starts running, the yaw rate sensor 11
The yaw rate initial correction γ _a1 corrected by the detected yaw rate initial correction means 16 because the ambient temperature change is still small.
Has little error. Therefore, calculated yaw rate error learning section 17 at this time, it learns the errors proportional to the speed of the vehicle calculated yaw rate gamma _b of the yaw rate calculating means 14 is calculated on the basis of the initial correction detection yaw rate gamma _a1. That is, while the vehicle is running, the left and right wheel speeds V _a , V _b
The yaw rate γ _b calculated by the yaw rate calculating means 14 from the difference has an error proportional to the vehicle speed under the influence of the wear amount of the tire, and the error value C is obtained by subtracting the initial correction detected yaw rate γ _a1 from the yaw rate γ _{b. Find b} . Then, a predetermined time (for example, 10
After a lapse of 0 second), the calculated yaw rate correction means 18 corrects the calculated yaw rate γ _b calculated by the yaw rate calculation means 14 based on the error value C _b obtained by the calculated yaw rate error learning means to obtain a corrected calculated yaw rate γ _b1 . .

After a lapse of a predetermined time from the start of traveling of the vehicle, during traveling, the detected yaw rate learning means 19 corrects the calculated calculated yaw rate γ _b1 corrected by the calculated yaw rate correcting means 18.
The initial corrected detected yaw rate γ _a1 corrected by the detected yaw rate initial correcting means 16 based on the above is learned. That is, when a predetermined time elapses after the vehicle starts running, the engine or the like warms up and the temperature around the yaw rate sensor 11 changes (rises), and the temperature change (rise) affects the yaw rate sensor 11. come. Therefore, obtaining an error value C _d by subtracting the correction calculating yaw rate gamma _b1 from the initial correction detection yaw rate gamma _a1. The detected yaw rate correction means 20 calculates the error value C of the detected yaw rate learning means 19.
Based on _d , the initial correction detected yaw rate γ _a1 is corrected to obtain the corrected detected yaw rate γ _a2 .

Here, the control flow of the above-described vehicle yaw rate calculation device of the present embodiment will be described with reference to a flowchart. As shown in FIG. 2, at step S1, the load yaw rate gamma _a vehicle yaw rate sensor 11 detects, in step S2, the vehicle speed V is greater than zero the vehicle speed sensor (not shown) has detected, i.e., the vehicle is It is determined whether the vehicle is running. In this step S2, When the vehicle is stopped, the process proceeds to step S3, performing the following steps S4, S5, S6 yaw rate gamma _a learning correction yaw rate sensor 11 is detected by. That is, in step S4, when the temperature change is small stop around the yaw rate sensor 11 to not like the engine warms, the error value C _a yaw rate gamma _a yaw rate sensor 11 detects is learned such that 0 determined, at step S5, the detected yaw rate gamma _a corrected based on the error value C _a, in step S6, the memory detection yaw rate gamma _a1 were initial correction.

On the other hand, when the vehicle speed V detected by the vehicle speed sensor becomes greater than 0 in step S2 and the vehicle starts running, a timer is started in step S6. And
If not, the timer counts 100 seconds at step S7, the following steps S8, S9, S10 at the left and right wheel speeds V _a, the yaw rate calculation means from V _b 1
4 performs learning correction of the yaw rate γ _b was calculated. That is,
In step S8, when the left and right wheel speeds V _a and V _b detected by the wheel speed sensors 12 and 13 are read, step S9 is performed.
Then, the yaw rate γ _b of the vehicle is calculated from the difference between the left and right wheel speeds V _a and V _b , and in step S10, the initial correction detection yaw rate γ already obtained from the calculated yaw rate γ _b having the influence of the amount of tire wear. By subtracting _a1 ,
Performs learning for determining the error value C _b. The learning of the calculated yaw rate γ _b is performed for 100 seconds.
An average during that time may be obtained.

Thus, the calculated yaw for 100 seconds
Late γ_bFrom the error value C_bIs determined, and the process proceeds to step S7.
When the timer counts 100 seconds, step S11
Use to reset the timer. Then, in step S12,
This error value C_bYaw rate γ calculated based on_bCorrect
And the correction calculation yaw rate γ_b1Ask for. Then the vehicle
While driving, the engine etc. warms up and the yaw rate
The temperature around the sensor 11 rises and the initial correction detection yaw
G_a1Has this effect. Therefore, in step S13
Is the initial correction detection yaw rate γ_a1Correction calculation from yaw
Late γ_b1Is subtracted to obtain the error value C_dLearning in search of
You. Then, in step S14, the initial correction detection yaw
Ito γ_a1From the error value C_dIs subtracted and corrected.
-Rate γ _a2And output.

As described above, the yaw rate of the vehicle according to this embodiment is
In the arithmetic unit, the yaw rate sensor 11 detected
Detection yaw rate γ_aAnd the true value of the yaw rate is zero
Detects when stopped, performs learning correction of the detection reference point, and performs initial correction detection.
Yaw rate γ_a1While the left and right wheel speeds V_a,
V_bYaw rate γ calculated from the difference_bThe vehicle starts
Within a predetermined time after this, the calculated yaw rate γ_bFrom the initial supplement
Positive detection yaw rate γ_a1Is subtracted from the learning correction to correct the wheel friction.
Eliminates errors due to wear and calculates the corrected yaw rate γ _b1Seeking
As a result, the initial correction detection yaw rate γ
_a1And correction calculation yaw rate γ_b1Learning correction based on
Highly accurate yaw rate γ_a2I want to ask. Follow
To the detection error due to temperature change and the speed due to the amount of wheel wear.
Eliminating proportional errors ensures that high-precision
You can ask for a yaw rate.

[0020]

As described in detail in the above embodiment, according to the vehicle yaw rate calculation device of the present invention, the vehicle yaw rate sensor, the left wheel speed sensor and the right wheel speed sensor detect the vehicle speed difference from the left and right wheel speed sensors. A yaw rate calculating means for calculating the yaw rate of the vehicle, and learning and correcting the error of the detected yaw rate when the vehicle stops, and calculating the yaw rate based on the detected yaw rate corrected within a predetermined time after the vehicle starts running. After the elapse of a predetermined time, the calculated yaw rate is corrected based on the learning value, and the detected yaw rate initially corrected based on the calculated yaw rate corrected during traveling of the vehicle is learned and corrected. As a result, when the vehicle is stopped, the detected yaw rate is not affected by temperature changes by correcting the detected yaw rate error. Within a predetermined time after the vehicle starts running, the calculated yaw rate is corrected based on the initially corrected detected yaw rate to obtain a calculated yaw rate that is not affected by the speed change. Since the yaw rate is obtained from the detected yaw rate and the correction calculation yaw rate, a high-accuracy yaw rate free from errors due to temperature changes and errors due to wheel wear can be calculated.

[Brief description of the drawings]

FIG. 1 is a control block diagram illustrating a yaw rate calculation device for a vehicle according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a control method by the yaw rate calculation device of the vehicle according to the embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 yaw rate sensor 12, 13 wheel speed sensor 14 yaw rate calculating means 15 initial detected yaw rate error learning means 16 detected yaw rate initial correcting means 17 calculated yaw rate error learning means 18 calculated yaw rate correcting means 19 detected yaw rate learning means 20 detected yaw rate correcting means

Claims (1)

[Claims] 1. A yaw rate sensor for detecting a yaw rate of a vehicle, a wheel speed sensor for detecting left and right wheel speeds of the vehicle, and a yaw rate of the vehicle based on a difference between left and right wheel speeds detected by the wheel speed sensors. A yaw rate calculating unit, an initial detection yaw rate error learning unit that learns a yaw rate error detected by the yaw rate sensor when the vehicle stops, and a yaw rate detected by the yaw rate sensor based on a learning value of the initial detection yaw rate error learning unit. A detected yaw rate initial correction means for correcting the detected yaw rate based on the detected yaw rate corrected by the detected yaw rate initial correction means within a predetermined time after the vehicle starts running. Calculating yaw rate error learning means for learning an error proportional to A calculated yaw rate correction means for correcting the calculated yaw rate calculated by the yaw rate calculation means based on a learning value of the calculated yaw rate error learning means after a lapse of a predetermined time from the start of travel, and the calculated yaw rate during the travel of the vehicle. Detection yaw rate learning means for learning the detected yaw rate corrected by the detected yaw rate initial correction means based on the calculated yaw rate corrected by the correction means,
A yaw rate calculating device for a vehicle, comprising: detected yaw rate correction means for correcting the detected yaw rate corrected by the detected yaw rate initial correction means based on the learning value of the detected yaw rate learning means.